Of course that didn't help, because you cannot calibrate the battery, especially not by deleting Android's batterystats.bin file (which is what those "calibration" apps do).

Do you have any ideas?

You could try opening the tablet (only do that if you feel comfortable with the idea and don't mind potentially losing your warranty). Then unplug the battery for a while (it's not soldered as in previous tablets, so that's convenient).Maybe that'll help.

Maybe someone could adapt the instruction from the link above for our device?

The "echo B820 > /sys/devices/i2c-2/2-0034/axp20_reg" stuff directly accesses hardware registers of the AXP202 power management chip. The Hero 1 does not use this chip, so this won't work.

I ran into this problem early on in the development of my ROM. I'm not sure exactly what caused it but there were issues with the framework-res. To fix it I followed all the steps in the automated CM10 install thread, including the two flashes of the 1a.factoryromresets.zip in the first step. The battery icon was working in CM10 after that. Of course now I'm using my own Anti-Hero ROM with the 1% battery mod and that works fine as well.

If I've helped you set-up your new tablet, unbrick your device or if you use and enjoy my Amlogic AML8726-M Series ROM'splease consider a donation. My ROMS - *Crystal Clear (Ainol Crystal) *Anti-Hero (Ainol Hero) *Elenari (Ainol Elf2) *Astronautica (Ainol Aurora2) *Karbonn Custom (Karbonn SmartTab ST8 & ST10)My DEVICES - *HP Touchpad *Ainol Crystal *Ainol Hero *Ainol Fire *Cube U30GT Mini-S *Nexus 7 (2013) I don't respond to most PM's just because of the amount I get. If you have a question the best way to get an answer is to post in one of my threads.

I ran into this problem early on in the development of my ROM. I'm not sure exactly what caused it but there were issues with the framework-res. To fix it I followed all the steps in the automated CM10 install thread, including the two flashes of the 1a.factoryromresets.zip in the first step. The battery icon was working in CM10 after that. Of course now I'm using my own Anti-Hero ROM with the 1% battery mod and that works fine as well.

First time i've heard of the factoryromreset.zip.. sir fuser, do you think it help solve g sensor issue? Will that zip reset the driver for the bma chip?

My Novo 10 Hero has the same problem too. Sometime ago it started to show the battery indicator all the time. I would not mind if it was just the problem of the wrong indication but I’ve also seen that when I “Power Off” the tablet it completely discharges from 100% to 0% in several hours, as shown on the screenshots, and that is really a problem. (When the tablet is in sleep mode it discharges about 1.5& per hour).
Since then I have flashed several different FWs, from the original 1219 to 0308, to Bloatfree 0308, to 1115, to CM10. I have opened the tablet and checked inside, everything looks OK, no loose connectors, no cold soldering joints, no visibly broken components. I have taken the battery connector out for a while and plug it in again.
No luck, all the above operations have not resolved the problems.
If you would advise something else to help, I would be very pleased to try it before I send the tablet back for repair.